scsi: lpfc: Raise maximum NVME sg list size for 256 elements

Raise the maximum NVME sg list size allowed to 256 elements.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>